<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        const num = 100;

        console.log(num);//输出变量值 100
        console.log(1 + 1);//输出表达式返回值 2
        console.log(200);//输出值
        console.log("jack");//输出值
    </script>
</body>

</html>